This application requests funds to purchase a Cytomation MoFlo MLS (MoFlo). The MoFlo is equipped with three lasers, two scatter and six fluorescence detectors, and can sort 2, 3 or 4 ways at a rate of 25,000 cells/second and clone cells into multi-well plates and slides. The MoFlo will be used to identify, quantify and assess the functions of cell subpopulations in peripheral blood, lymph nodes, thymus, bone marrow, amniotic fluid, chorion and decidua, corpus luteum, and human, monkey and mouse brain. When required, subpopulations characterized by multi-parameter analyses will be sorted in bulk or cloned for functional or genetic analyses. With the availability of a high sorting speed, the MoFlo will provide adequate numbers of purified cells which currently would take up to 50 times longer to sort with the EPICS C. The MoFlo will replace a Coulter EPICS C which was purchased in 1984. By present day standards, the EPICS is inadequate, being limited to two color analyses and slow sorting speed (500 cells/second). The MoFlo will be used by 17 investigators from the Oregon Regional Primate Research Center (ORPRC), the Oregon Health Sciences University (OHSU) and the Veterans Administration Medical Center (VAMC). Research programs taking advantage of the flow cytometer will be in the areas of: (1) infectious diseases using human or animal models to study SIV, HIV, typed D retrovirus, rhesus Kaposi's sarcoma herpesvirus, herpes simplex virus and adenovirus; (2) reproductive research studying the corpus luteum, primate parturition, causes of male infertility and cloning of non-human primates; and (3) other research studying coronary disease, ischemic damage of the mouse brain and experimental allergic encephalomyelitis in rats. The MoFlo will significantly upgrade the ORPRC's flow cytometry capability and provide a major resource for the Portland biomedical research community. An Internal Advisory Committee will initially develop and institute policies of usage and meet periodically to evaluate these policies. An operator will be assigned to operate, maintain and coordinate the use of the flow cytometer. A training program will be instituted to acquaint investigators with the analytical part of the CyCLOPS software so they may manipulate flow data stored as list mode files. In addition, for interested users, training will be offered in operating the MoFlo to acquire data and/or sort cells. The ORPRC will share in the cost of purchasing the MoFlo, provide for a flow cytometer operator and purchase an annual maintenance agreement to maintain the instrument at peak efficiency.